linux/kernel/dma/mapping.c, branch v5.11

dma-mapping: Allow mixing bypass and mapped DMA operation

2020-11-27T09:33:40Z

At the moment we allow bypassing DMA ops only when we can do this for the entire RAM. However there are configs with mixed type memory where we could still allow bypassing IOMMU in most cases; POWERPC with persistent memory is one example. This adds an arch hook to determine where bypass can still work and we invoke direct DMA API. The following patch checks the bus limit on POWERPC to allow or disallow direct mapping. This adds a ARCH_HAS_DMA_MAP_DIRECT config option to make the arch_xxxx hooks no-op by default. Signed-off-by: Alexey Kardashevskiy Signed-off-by: Christoph Hellwig

dma-mapping: move large parts of to kernel/dma

2020-10-06T05:07:06Z

Most of the dma_direct symbols should only be used by direct.c and mapping.c, so move them to kernel/dma. In fact more of dma-direct.h should eventually move, but that will require more coordination with other subsystems. Signed-off-by: Christoph Hellwig

dma-mapping: move dma-debug.h to kernel/dma/

2020-10-06T05:07:05Z

Most of dma-debug.h is not required by anything outside of kernel/dma. Move the four declarations needed by dma-mappin.h or dma-ops providers into dma-mapping.h and dma-map-ops.h, and move the remainder of the file to kernel/dma/debug.h. Signed-off-by: Christoph Hellwig

dma-mapping: split

2020-10-06T05:07:03Z

Split out all the bits that are purely for dma_map_ops implementations and related code into a new header so that they don't get pulled into all the drivers. That also means the architecture specific is not pulled in by any more, which leads to a missing includes that were pulled in by the x86 or arm versions in a few not overly portable drivers. Signed-off-by: Christoph Hellwig

dma-mapping: add new {alloc,free}_noncoherent dma_map_ops methods

2020-09-25T04:20:47Z

This will allow IOMMU drivers to allocate non-contigous memory and return a vmapped virtual address. Signed-off-by: Christoph Hellwig

dma-mapping: add a new dma_alloc_pages API

2020-09-25T04:20:47Z

This API is the equivalent of alloc_pages, except that the returned memory is guaranteed to be DMA addressable by the passed in device. The implementation will also be used to provide a more sensible replacement for DMA_ATTR_NON_CONSISTENT flag. Additionally dma_alloc_noncoherent is switched over to use dma_alloc_pages as its backend. Signed-off-by: Christoph Hellwig Acked-by: Thomas Bogendoerfer (MIPS part)

dma-mapping: remove dma_cache_sync

2020-09-25T04:20:46Z

All users are gone now, remove the API. Signed-off-by: Christoph Hellwig Acked-by: Thomas Bogendoerfer (MIPS part)

dma-direct: Fix potential NULL pointer dereference

2020-09-17T16:43:20Z

When booting the kernel v5.9-rc4 on a VM, the kernel would panic when printing a warning message in swiotlb_map(). The dev->dma_mask must not be a NULL pointer when calling the dma mapping layer. A NULL pointer check can potentially avoid the panic. Signed-off-by: Thomas Tai Reviewed-by: Konrad Rzeszutek Wilk Signed-off-by: Christoph Hellwig

dma-mapping: move dma_common_{mmap,get_sgtable} out of mapping.c

2020-09-11T07:14:56Z

Add a new file that contains helpers for misc DMA ops, which is only built when CONFIG_DMA_OPS is set. Signed-off-by: Christoph Hellwig Reviewed-by: Robin Murphy

dma-mapping: add a dma_ops_bypass flag to struct device

2020-07-19T07:29:29Z

Several IOMMU drivers have a bypass mode where they can use a direct mapping if the devices DMA mask is large enough. Add generic support to the core dma-mapping code to do that to switch those drivers to a common solution. Signed-off-by: Christoph Hellwig Tested-by: Alexey Kardashevskiy Reviewed-by: Alexey Kardashevskiy